Mo. Rev. Stat. § 292.370
No employee shall take or be allowed to take any food or drink of any kind into any room or apartment in which any process or manufacture or labor referred to in section 292.310 is carried on, or in which poisonous substances or injurious or noxious fumes, dusts or gases are present as the result of such work or process being carried on in such room or apartment, and the employees shall not remain in any such room or apartment during the time allowed for meals, and suitable provision shall be made and maintained by the employer for enabling the employees to take their meals elsewhere in such place of employment, and a sufficient number of sanitary drinking fountains containing wholesome drinking water, and providing ice for same, shall be provided and maintained for the use of the employees within reasonable access and without cost to them.
§ 292.370, RSMo